Subject: OLSR sequence numbers

From: Joe Macker <[email-masked]>
Date: Tue, 14 Aug 2001 15:22:01 -0400

I have a quick question about OLSR.

The recent OLSR drafts seem to be indicate that the monotonically 
increasing sequence number space is common across message types being 
sourced.  In some experimental versions, the HELLO sequence number was 
assumed unique and used for hysteresis estimations.  I want to make sure we 
are interpreting the ID correctly as written more recently, that the 
intention is to have sequence numbers be common across message types.  This 
answer has some L3-implemented link hysteresis calculation implications.

-joe

---

From: "Philippe Jacquet" <[email-masked]>
Date: Wed, 22 Aug 2001 11:57:03 +0200

Dear Joe,

Yes, we thought it was simpler to keep it that way, since we originally push
toward a common sequence number for all control messages. But in this case
all control traffic from tail node is used to link hysterisis calculation.
Among this traffic, the multihop control messages need specific treatment
because you may receive them indirectly. To solve this case you just assume
a link miss when you receive the message indirectly for the first time. That
way the duplicate table should suffice to help the link hysterisis
calculation.

I agree it is a little different than only using hellos, because it takes
advantage of using more traffic to sample the link. However I don't expect
big discrepancies since multihop control message should be less frequent.
Otherwise we have to include a separate sequence number in hellos.

Philippe

---

From: Joe Macker <[email-masked]>
Date: Thu, 23 Aug 2001 12:58:17 -0400

>Otherwise we have to include a separate sequence number in hellos.

I agree with this. I just wanted to make sure I was interpreting the newer 
specification as intended.  It's also possible to develop a link hysteresis 
algorithm that does necessarily require unique hello sequence numbers, but 
requires some other knowledge  (e.g., hello interval 
estimator,etc).  Actually, we have something like this working in ns2, but 
I potentially like your idea above that includes all messages..

---

From: Joe Macker <[email-masked]>
Date: Thu, 23 Aug 2001 18:55:17 -0400

At 12:58 PM 8/23/2001 -0400, Joe Macker wrote:
>specification as intended.  It's also possible to develop a link 
>hysteresis algorithm that does necessarily require

should read "does not necessarily"

>unique hello sequence numbers, but requires some other knowledge  (e.g., 
>hello interval estimator,etc).  Actually, we have something like this 
>working in ns2, but I potentially like your idea above that includes all 
>messages..